MC4 connectors

[Crowz]

This is the cable that I bought off amazon.

https://www.amazon.com/gp/product/B01D7VBU8Y/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

I don't see any info on there about the ends used. See if you can find something in case I overlooked it.

 

[stienman]

I know how it's supposed to work, what I'm saying is the prongs on ALL of the wrenches I buy are too wide to fit into the connector.

On the connectors with the shrouded release tabs (where the plastic bar covers the entire release tab) I use the tool at an angle to go around the shroud, so the tool squeezes the shroud and the shroud presses the tabs in far enough to release. It's not a clear, quick, easy disconnect, I usually have to wriggle things to get the tabs pressed enough to release, but it's easier than trying to fit needle nose pliers in there. I've considered cutting the shrouds off, but haven't decided to do so.

I don't like that flavor of "MC4 alike" connectors, but I'm not going to spend time and money replacing them without cause. I don't assemble/disassemble the connectors more than a few times in their lifetime, so it's just not an issue.

 

[stienman]

The mismatched connectors from different brands allowed moisture to penetrate the seal within the housing.

Well that's concerning. I suppose I'll need to examine my connectors to confirm they are in good condition and aren't leaking.

I'm guessing they are leaking/corroded, though, because while the solarcity H6 inverter ran without issue the first year I used it when the panels were first assembled, I turned it off for several months and recent reconnection causes it to throw arc fault errors on the solar arrays.

Guess I better choose a connector style going forward and just plan on a replacement party sometime in the next year for the existing panels.

 

[Kenny_]

I know how it's supposed to work, what I'm saying is the prongs on ALL of the wrenches I buy are too wide to fit into the connector.

Yes I've found the same sort of thing just in my initial hookup work....very annoying...

 

[ampsarus]

All of my MC4's are of the same generic no name brand. I wonder if it would be wise to use dielectric grease to lube the o-rings and mating contact surfaces, and to block moisture ingress.

 

[fafrd]

Well that's concerning. I suppose I'll need to examine my connectors to confirm they are in good condition and aren't leaking.

I'm guessing they are leaking/corroded, though, because while the solarcity H6 inverter ran without issue the first year I used it when the panels were first assembled, I turned it off for several months and recent reconnection causes it to throw arc fault errors on the solar arrays.

Guess I better choose a connector style going forward and just plan on a replacement party sometime in the next year for the existing panels.

If you’ve got mismatched MC4-type connectors and are concerned about corrosion and increased resistance, one relatively easy way to check for signs of excessive heat is using a thermal camera.

If your MC4-type connectors are all cable-type (no housing-type MC4s), it’s easy enough to pick up a bulk pack of your preferred UL-listed MC4-type connector (which will usually come with its own pair of wrenches) and just replace both ends.

 

[fafrd]

All of my MC4's are of the same generic no name brand. I wonder if it would be wise to use dielectric grease to lube the o-rings and mating contact surfaces, and to block moisture ingress.

I don’t believe dielectric grease is generally recommended.

If they are matching, that should remove the concern regarding moisture ingress, but only if they are UL-listed.

So if your no-name brand does not have any claim to UL, I’d be concerned about that and consider upgrading to Staubli MC4 or Amphenol H4 or at least any other brand with UL certification.

If it’s easy for you to monitor the heat of your connectors trough the highest-production part of the day, you can probably stay safe with what you’ve got by putting in that effort at least annually.

But ‘set it and forget it’ is not a good strategy when using generic no-name non-UL MC4-type connectors…

 

[fafrd]

None of the panels I have list the mc4 connector info.

This is from the chinese panel that was on the other end of the cable.

View attachment 165455

I also went and looked at my renogy info and windy nation panels I have and no mention of the mc4 manufacturer used. So I would say the connector used being on the info sheet isn't that common at least on the panels I have its not there.

If you call Windy Nation they should be able to tell you what they are using.

While many companies say ‘MC4’ when they mean ‘MC4-compatible’ Windy Nation is a reputable solar company, so if their documentation states ‘MC4’ I’m guessing they are using try’s Staubli / MultiContact MC4 connectors.

Let us know what you learn.

If you know you will never be collecting on a warranty claim in your Noname chinese panels, you should consider purchasing matching connectors from Windy Nation and upgrading the panel connectors to match what Windy Nation uses for their cables.

 

[fafrd]

This is the cable that I bought off amazon.

https://www.amazon.com/gp/product/B01D7VBU8Y/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

I don't see any info on there about the ends used. See if you can find something in case I overlooked it.

The Amazon add states ‘UL’ and going to their website I see they sell MC4 connectors that are also UL: https://www.windynation.com/products/pv-solar-connectors

It’s a near-certainty that the UL-listed connectors they sell are matched with the UL-listed connectors used on the cables they sell but it’s easy enough to be certain.

I’d suggest you contact Windy Nation (805 323 6445) and ask them who manufactures the MC4-type connectors used of their solar cables and who manufactures the MC4-type connector they sell and where you can find detailed datasheets / specifications on those connectors

MultiContact invented the MC4 connector and Staubli bought he MultiContact company. Here is Staubli’s MC4 connector datasheet / catelog including specifications: https://www.staubli.com/content/dam/spot/PV_SOL-LVDC-en.pdf

From what Windy Nation presents as far as specs, I won’t be surprised if you learn they are using Staubli (and if not, it is likely Amphenol or another well-reputed brand with true UL listing).

 

[floridafraze]

I recently bought ten of the Hyundai 305w PV panels from Signature Solar and they all have this bloody MC4 style connectors (attached). Looks like even if you cut off the outer plastic bands it will still be a bit difficult to separate them. I was all set to run a brief and temporary charge test of my EG4-6000EX-48 using a handful of the new panels but when I spotted these dang connectors it stopped me dead in my tracks. I wouldn't be able to quickly get them back apart! These are HEAVY DUTY, with no chance of bending/compressing them and even very little finger room to maneuver with the bands cut/removed. I little grinding might help.

My arrays are planned to always be temporarily installed in the solar farm in my backyard and removed to the safety of my shop when a hurricane threatens (I'm in FL). This type of nonsense just adds another level of frustration. I should be busy doing other stuff rather than having to stop and figure out how to modify/correct things like this.

Frustrating...

I haven't investigated yet to see if they sell yet another specialty tool for them.